1. Field of the Invention
This invention relates to a novel method and container for the preservation of produce. More particularly, it relates to irradiation of produce with electromagnetic radiation having specific wave lengths for retaining the freshness of produce, such as vegetables, fruits, and certain plants.
2. Prior Art
Currently, vegetables are preserved in plastic bags with nitrogen, excluding oxygen to avoid spoilage. This is expensive and labor-intensive. A more recent approach to preserve food is to use irradiation to dry and store food as disclosed in U.S. Pat. No. 5,707,911. Another method is to use radioactive substances to irradiate produce and in combination with an oxygen-reactive chemical to keep food fresh, as disclosed in U.S. Pat. No. 5,030,510. The latter method is not safe in view of the radioactive substance. Thus there is a need for an economical and safe method to preserve produce.
The object of this invention is to use a mineral, spinel, to irradiate produce, thereby keeping it fresh.
Spinels are known for their antimicrobial properties as shown in applicant""s U.S. Pat. No. 6,051,246. Infrared radiation is known for its beneficial effects in sterilization of food. However, no method or product in prior art is known using spinel compounds of the general formula AB2O4 as disclosed herein for preserving produce.
It has now been discovered that far-infrared radiation emitted by spinels having the general formula AB2O4 preserves the freshness of produce. The radiation should be in the wavelength range from 3-30 microns, and preferably 3-18 microns. The spinel AB2O4 powder mixed with resin is coated on a container such as a bag or box, and the fresh produce is stored in such a container.